This invention relates to curable resin compositions to be used for forming coating with excellent abrasion resistance on the surface of plastic, inorganic glasses or metals.
Transparent plastics or so-called organic glasses are light materials having high impact strength and excellent workability and therefore are used in various fields such as glasses (panes and windshields) for vehicles interior decorations of buildings, glasses for meters and gauges, lenses of eyeglasses, etc. However, although plastics are tough and do not easily crack, they are inferior in surface hardness, especially in abrasion resistance and are easily scratched.
On the other hand, the inorganic glass has excellent resistance against scratch or abrasion, but it is dissatisfactory in that due to its poor impact strength it easily breaks and it is ground by repeated light impact applied on the surface thereof and is frosted. Most of metals are dissatisfactory, too, in that the surface thereof is rather easily scratched and abraded.
A measure often resorted to in order to improve abrasion resistance of the surface of solid materials is to coat the surface with a coating materials having good abrasion resistance. Hitherto, many attempts have been made to find excellent coating materials.
Among the known synthetic plastics, three dimensional polymers such as polymers of diethyleneglycol bis-allyl-carbonate or polyester resins and other thermosetting resins have the best abrasion resistance. And there has been found no coating materials having abrasion resistance superior to that of those polymers and comparable to that of inorganic glasses. Moreover, coating materials must be excellent in not only abrasion resistance but also in other various properties such as thermal resistance, chemical resistance, weatherability, etc. and thus these properties must be well balanced. Otherwise they cannot be used for practical purpose. From this view point, all the prior art coating materials are dissatisfactory and scarcely useful.
Accordingly the object of this invention is to provide a curable resin composition used for forming a coating having superior abrasion resistance well-balanced with other practical properties.